For most of us middle-aged couch potatoes, changing to healthy lifestyles seems about as possible as making our first million.

We’ve had these bad habits a long time, and we’re rather fond of them. The thought of eating healthily and taking regular exercise doesn’t inspire us to put on our jogging shoes and grab a lettuce – it makes us want to hide under the bed with a plate of chips.

When we were younger, it didn’t seem to matter that much. We could always start a fitness campaign tomorrow. But now we’re middle-aged, we keep seeing news items of people who’ve died of heart disease at the age we’re at now, and we’re starting to panic that we’ve left it too late. Our drinking and smoking habits have crept up over the years, and it’s costing us a fortune to feel this lousy in the mornings.